The present invention relates to an electronic component material containing pest repellent effective for repelling pest insects in electronic appliances used in professional kitchen and food industry, that is, electronic appliances of which reliability may be spoiled by pest insects, and electronic components using the same.
Hitherto, environments inhabited excessively by cockroaches and other harmful insects were not assumed, and it was very rare to encounter trouble of electronic appliance due to dead bodies and excrement of insects. Accordingly, pest control measures were not taken within the electronic appliances, but the pest control measures were applied in the entire environments.
However, as the electronic appliances are diversified, and the restaurant industry is grown widely, there is a mounting demand for reliability of electronic appliances used in professional kitchens and food industry (for example, electric cooking tools and kitchen telephones), and the pest control measures are needed in the electronic appliances themselves.
For example, a conventional cockroach repellent was applied in necessary places by adhering, coating, or placing. If the conventional cockroach repel lent is directly used in the members of electronic components, it is evaporated and decomposed in the manufacturing process of electronic appliances due to heat load of solder reflow or solder flow. Therefore, the cockroach repellent cannot be directly used in the printed wiring board. On the other hand, the technique for applying a mixed material of resin and cockroach repellent after fabricating the printed wiring board through heat load process was proposed, for example, in Japanese Laid-open Patent No. 8-275713 and Japanese Laid-open Patent No. 8-275714. These prior arts disclose the packing material or sealing material by molding a silicone resin containing an absorbent absorbing a cockroach repellent and a bleed-out agent into a specified shape, and the molded material is put in the appliance. In these prior arts, moreover, a paint composed of a cockroach repellent and a urethane resin dissolved in thinner is applied on the appliance, and the coat film drying the paint is presented. However, when such prior arts are applied in the printed wiring board and electronic component, the adhesion of the cockroach repellent which is the minimum limit of reliability of such printed wiring board and electronic component cannot be maintained, and further it was complicated and difficult in the manufacturing process of electronic appliances to apply such conventional resin after the heat load process of mounting components.
In the case of the printed wiring board using such conventional cockroach repellent, at the maximum reaching temperature of 240xc2x0 C. of the solder reflow or solder flow temperature of 250xc2x0 C. (set temperature of solder bath), the cockroach repellent is partly evaporated and decomposed, and when the performance of cockroach repellent deteriorates significantly. Besides, after similar heat load, the adhesion of the cockroach repellent on the printed wiring board and electronic component cannot be guaranteed.
It is hence an object of the invention to present an electronic component material containing pest repellent having a pest control effect even after solder reflow and solder flow and capable of assuring reliability and adhesion when used in electronic appliances, and an electronic component using the same.
An electronic component material of the invention comprises a resin which can be crosslinked and cured, a pest repellent contained in the resin, and a filler contained in the resin, in which a pest repelling layer is formed by curing the resin by crosslinking chemical reaction.
In this constitution, by forming the pest repelling layer containing the filler, the pest repelling layer does not deteriorate at all even after heat load of high temperature when manufacturing electronic appliances such as printed wiring boards, and the pest repelling layer maintaining an excellent stress relaxation and superior adhesion is obtained. Moreover, in the cleaning process by solvent after soldering, the pest repelling layer and the pest repellent are not impaired by the solvent.
Preferably, the curable resin contains epoxy resin and hardener.
Preferably, the curable resin contains epoxy acrylate, reactive diluent and light initiator. In this constitution, when applied in an electronic component, the adhesion of the pest repelling layer is further enhanced, and when cleaning at high temperature in the soldering process, the pest repelling layer having an excellent pest repelling effect is obtained. Further, when curing, part of the pest repellent is moved to the surface of the pest repelling layer, and is dispersed in the entire area, and the repelling effect of cockroaches and other insects is extremely exhibited.
An electronic component of the invention comprises:
(a) a printed wiring board having an electric insulating board and a conducive layer disposed on the surface of the electric insulating board, and
(b) a pest repelling layer disposed on the surface of the printed wiring board,
in which the pest repelling layer contains a crosslinked and cured resin, and a pest repellent dispersed and disposed in the resin. The pest repelling layer also functions as an electric insulating layer.
In this constitution, the printed wiring board remarkably exhibiting the effects of repelling cockroaches and other insects is obtained. At the same time, since the pest repellent is fixed by the resin which is crosslinked and cured, when soldering other electronic components on the printed wiring board by high temperature solder, melting of resin and deterioration of pest repellent can be prevented, and the printed wiring board maintaining an excellent pest repelling effect against soldering is obtained. Moreover, after high temperature heat load and cleaning process in manufacture of printed wiring board, the pest repelling layer maintaining an excel lent stress relaxation and superior adhesion is obtained.
A manufacturing method of electronic component of the invention is a manufacturing method of electronic component having a pest repelling layer with a performance of repelling pest insects on the surface of a printed wiring board.
The method comprises:
(a) a step of adjusting an electronic component material having a pest repellent and a resin which can be crosslinked and cured,
(b) a step of applying the electronic component material at a specified position on the surface of the printed wiring board, and
(c) a step of forming the cured pest repelling layer, containing the pest repel lent, by crosslinking chemical reaction of the resin in the electronic component material on the printed wiring board.
According to this method, even after heat load or in cleaning process in manufacture of printed wiring board, the pest repelling layer having an excellent stress relaxation and superior adhesion is obtained. Moreover, the printed wiring board remarkably exhibiting the effects of repelling cockroaches and other pests can be manufactured at low cost. At the same time, since the since the pest repellent is fixed in the crosslinked and cured resin, when soldering other electronic components on the printed wiring board by high temperature solder, melting of resin and deterioration of pest repellent can be prevented, and the printed wiring board maintaining an excellent pest repelling performance even against soldering is obtained.
In this constitution, preferably, the electronic component material further contains a filler. The pest repelling layer further contains a filler.
By containing the filler, the mechanical strength of the pest repelling layer is improved, and the stress relaxation is enhanced, and the adhesion is further increased. Furthermore, the pest repellent is adsorbed on the filler such as silica or talc, and the filler component contributes to enhance the dispersion of the pest repellent.